Print out the nth row of Pascal's triangle.
Use zero-based indexing, so row 0 is [1]. Implement def pascal_row(n):, which accepts a non-negative integer and returns the row as a list of integers. Aim for O(n) auxiliary computation beyond the returned output, and do not construct the preceding rows.
The input is an integer n. Return a list containing the values in row n, from left to right.
def pascal_row(n):